Maynooth, Ontario climate data is summarized below. Average annual temperatures range from -1.3 °C (low) to 10.1 °C (high). Annual precipitation averages 574 Millimeters. Maynooth is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.73 °C | -5.26 °C | 0 mm |
| February | -16.39 °C | -4.75 °C | 0 mm |
| March | -9.56 °C | 1.96 °C | 10 mm |
| April | -2.43 °C | 9.87 °C | 57 mm |
| May | 4.22 °C | 17.88 °C | 72 mm |
| June | 9.63 °C | 21.98 °C | 76 mm |
| July | 11.79 °C | 24.2 °C | 88 mm |
| August | 11.05 °C | 23.23 °C | 82 mm |
| September | 6.33 °C | 18.79 °C | 70 mm |
| October | 1.57 °C | 11.5 °C | 79 mm |
| November | -4.59 °C | 4.66 °C | 40 mm |
| December | -11.32 °C | -2.7 °C | 0 mm |
| Annual | -1.3 °C | 10.1 °C | 574 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |